Poorly sited U.S. temperature instruments not responsible for artificial warming

Former TV weatherman Anthony Watts, who runs the popular global warming contrarian website, "Watts Up With That", was convinced that many of the U.S. network of surface weather stations had serious flaws in their siting that was causing an artificial warm bias in the observed increase in U.S. temperatures of 1.1°F over the past century. To address this concern, Watts established the website surfacestations.org in 2007, which enlisted an army of volunteers to travel the U.S. to obtain photographic evidence of poor siting of weather stations. The goal was to document cases where "microclimate" influence was important, and could be contaminating temperature measurements. (Note that this is a separate issue from the Urban Heat Island, the phenomenon where a metropolitan area in general is warmer than surrounding rural areas). Watts' volunteers--650 strong--documented the siting of 865 of the 1,218 stations used in the National Climatic Data Center's U.S. Historical Climatology Network (USHCN) for tracking climate change. As reported in Watt's 2009 publication put out by the Heartland Institute, the volunteers "found stations located next to the exhaust fans of air conditioning units, surrounded by asphalt parking lots and roads, on blistering-hot rooftops, and near sidewalks and buildings that absorb and radiate heat." Watts surmised that these poorly-sited stations were responsible for much of the increase in U.S. temperatures over the past century, due to "a bias trend that likely results from the thermometers being closer to buildings, asphalt, etc." Watts concluded, "the U.S. temperature record is unreliable. And since the U.S. record is thought to be the best in the world, it follows that the global database is likely similarly compromised and unreliable".

Figure 1. A poorly sited temperature sensor in Marysville, California, used for the USHCN. The sensor is situation right next to an asphalt parking lot, instead in the middle of a grassy field, as it is supposed to be. The sensor is also adjacent to several several air conditioners that blow their exhaust into the air nearby. Image credit: surfacestation.org.

Analysis of the data disagrees with Watts' conclusionWhile Watts' publication by the Heartland Institute is a valuable source of information on siting problems of the U.S. network of weather stations, the publication did not undergo peer-review--the process whereby three anonymous scientists who are experts in the field review a manuscript submitted for publication, and offer criticisms on the scientific validity of the results, resulting in revisions to the original paper or outright rejection. The Heartland Institute is an advocacy organization that accepts money from corporate benefactors such as the tobacco industry and fossil fuel industry, and publishes non-peer reviewed science that inevitably supports the interests of the groups paying for the studies. Watts did not actually analyze the data to see if taking out the poorly sited surface stations would have a significant impact on the observed 1.1°F increase in U.S. temperatures over the past century. His study would never have been publishable in a peer-reviewed scientific journal.

Figure 2. Annual average maximum and minimum unadjusted temperature change calculated using (c) maximum and (d) minimum temperatures from good and poor exposure sites (Menne 2010). Poor sites showed a cooler maximum temperature compared to good sites. For minimum temperature, the poor sites were slightly warmer. The net effect was a cool bias in poorly sited stations. The dashed lines are for stations ranked by NOAA, while the solid lines are for the stations ranked by surfacestations.org.

Fortunately, a proper analysis of the impact of these poorly-sited surface stations on the U.S. historical temperature record has now been done by Dr. Matthew Menne and co-authors at NOAA's National Climatic Data Center (NCDC). In a talk at last week's 90th Annual Meeting of the American Meteorological Society, Dr. Menne reported the results of their new paper just accepted for publication in the Journal of Geophysical Research titled, On the reliability of the U.S. Surface Temperature Record. Dr. Menne's study split the U.S. surface stations into two categories: good (rating 1 or 2) and bad (ratings 3, 4 or 5). They performed the analysis using both the rating provided by surfacestations.org, and from an independent rating provided by NOAA personnel. In general, the NOAA-provided ratings coincided with the ratings given by surfacestations.org. Of the NOAA-rated stations, only 71 stations fell into the "good" siting category, while 454 fell into the "bad" category. According to the authors, though, "the sites with good exposure, though small in number, are reasonably well distributed across the country and, as shown by Vose and Menne [2004], are of sufficient density to obtain a robust estimate of the CONUS average". Dr. Menne's study computed the average daily minimum and maximum temperatures from the good sites and poor sites. The results were surprising. While the poor sites had a slightly warmer average minimum temperature than the good sites (by 0.03°C), the average maximum temperature measured at the poor sites was significantly cooler (by 0.14°C) than the good sites. As a result, overall average temperatures measured at the poor sites were cooler than the good sites. This is the opposite of the conclusion reached by Anthony Watts in his 2009 Heartland Institute publication.

Why did the poorly sited stations measure cooler temperatures?The reason why the poorly-sites stations measured cooler temperatures lies in the predominant types of thermometers used at the two types of sites. An electronic Maximum/Minimum Temperature System (MMTS) is used at 75% of the poor sites. These MMTS sensors are attached by cable to an indoor readout device, and are consequently limited by cable length as to how far they can be sited from the building housing the indoor readout device. As a result, they are often located close to heated buildings, paved surfaces, air conditioner exhausts, etc. It turns out that these MMTS thermometers have a flaw that causes them to measure minimum temperatures that are slightly too warm, and maximum temperatures that are considerably too cool, leading to an overall cool bias in measured average temperatures. In contrast, only 30% of the "good" sites used the MMTS sensors. The "good" sites predominantly used Liquid in Glass (LiG) thermometers housed in wooden shelters that were more easily located further from the buildings where the observers worked. Since the poorly-sites stations were dominantly equipped with MMTS thermometers, they tended to measure temperatures that were too cool, despite their poor siting.

Figure 3. Comparison of U.S. average annual (a) maximum and (b) minimum temperatures calculated using USHCN version 2 temperatures. Temperatures were adjusted to correct for changes in instrumentation, station relocations, and changes in the time of observation, making the trend from good sites show close agreement with poor sites. Good and poor site ratings are based on surfacestations.org. For comparison, the data between 2004 - 2008 taken by the new high-quality U.S. Climate Reference Network (USCRN, black dashed line) is shown, and displays excellent agreement for that time period. Image credit: Menne 2010.

Independent verification of recent USHCN annual temperaturesClearly, the siting of many of the surface stations used to track climate change in the U.S. is not good. To address this issue, in 2004 NOAA created the U.S. Climate Reference Network, a collection of 114 stations in the continental United States for the express purpose of detecting the national signal of climate change. The stations were sited and instrumented with climate studies in mind, and can provide an extremely high-quality independent check on the old USHCN network. Each of 114 stations at 107 locations (some stations were installed as nearby pairs) is equipped with very accurate instruments in a triplicate configuration so that each measurement can be checked for internal consistency. As shown in Figure 3, the USCRN air temperature departures for 2004 - 2008 are extremely well aligned with those derived from the USHCN version 2 temperature data. For these five years, the the difference between the mean annual temperatures measured by the old USHCN compared to the new USCRN was just 0.03°C, with a mathematical correlation coefficient (r-squared) of 0.997. Menne et al. concluded, "This finding provides independent verification that the USHCN version 2 data are consistent with research-quality measurements taken at pristine locations and do not contain spurious trends during the recent past even if sampled exclusively at poorly sited stations. While admittedly this period of coincident observations between the networks is rather brief, the value of the USCRN as a benchmark for reducing the uncertainty of historic observations from the USHCN and other networks will only increase with time". The authors finally concluded, "we find no evidence that the CONUS temperature trends are inflated due to poor siting".

Crediting Anthony WattsThe surfacestations.org effort coordinated by Anthony Watts has made a valuable contribution to science, helping us better understand the nature of the errors in the U.S. historical temperature data set. In his talk last week at the AMS conference, and in the credits of his paper, Dr. Menne had some genuinely grateful comments on the efforts of Anthony Watts and the volunteers of surfacestations.org. However, as of this writing, Watts has made no mention on surfacestations.org or on wattsupwiththat.com of Dr. Menne's study.

I only make attacks against Conservatism and such, not the people themselves. And I only say ACT NOW because we can't afford to waste another decade, or even another year, because climate negotiations have failed and individuals need to speak up and act.

No, I wasn't talking about you. I was talking to you.

While you and I do get into lengthy debates about a few things on here, I don't think either of us has allowed it to go the way of attacks, name-calling, and such.

No you didn't I still dont know where the glacial opinions you posted last night came from - you said I was willfully trying to deceive with the melting pics I posted. The Pic were my response that warming was not occurring in Bolivia.

Last night it was said the warming maps were inaccurate.

posting pictures of glaciers from different distances is inaccurate.

again, can I have a reference to where I specifically said you were "willfully trying to deceive with the melting pics"and to where I "said the warming maps were inaccurate" ?

No you didn't I still dont know where the glacial opinions you posted last night came from - you said I was willfully trying to deceive with the melting pics I posted. The Pic were my response that warming was not occurring in Bolivia.

Quoting atmoaggie:Hmmm, you aren't going to make any friends like that...a bunch of contrarians in here and at least 2 pro-AGW act-now'ers that do the above all the time.

I only make attacks against Conservatism and such, not the people themselves. And I only say ACT NOW because we can't afford to waste another decade, or even another year, because climate negotiations have failed and individuals need to speak up and act.

Publication of deliberately false climate change data literally ought — i.e., MUST — be treated, not as a peccadillo, but as a Crime Against Humanity.

My remark here is not an expression of an emotion, but of an intellectual and humanitarian reaction of a scientist to falsification of data that could be as bad in its effect as long-term global warming itself, by permitting the latter to thrive, and acquire an egregious and panhumanly disastrous momentum.

If this were World War III such people would be shot, and with far, far greater warrant than even those human catastrophes.

A scientist is a kind of Protective Angel for Humanity. Why? Simply because he lives and breathes for Truth.

——— * ———

As for the falsifiers of data, or criminal social parasites, let me switch from the second to the first of my scientific careers, long ago at M.I.T., where I was — a then VERY rare! — theorist in neuroscience, trying to make sense of the human brain as a whole and all the astonishing behavior and abilities it gives rise to.

A SIDE interest of mine, then and later, was the queer and baffling, and decidedly chilling, phenomenon of the psychopath, a.k.a. sociopath. The essential trait of such people is that have little or no conscience, and yet they can be at the same time profoundly convincing to the layman — i.e., virtually all of us.

The incidence of these curious and horrific people in the body of the whole of humanity is estimated to be of the order of 1/200. This is misleading, however, because the pathology is a matter of degree, or properly illustrated by an intensity-frequency curve.

To put it simply, a psychopath can and does lie without a blink, either external or internal. And often does so for profit or simply out of total indifference to the harm he works upon the innocent and the virtuous.

I have little doubt that the purveyors of purposefully, and dangerously, falsified Global Warming data ARE in many instances psychopaths, whose falsifications tend to put ALL of us at risk.

Even heads of great corporations can be, in various ways and degrees, psychopathic. (Psychopathy probably had some partly useful — personal OR social — function in the long-ago past of Homo sapiens. It is certainly common enough in our politicians nowadays!)

— Patrick Michael Gunkel (Princeton, NJ)

POSTSCRIPT: Two decades ago I was neutral, but skeptical, about global warming. Later I realized that we simply could not tolerate the risks it potentially posed. One does not play games, or take chances, when essentially the whole of civilization and humanity MAY be in peril.

None of us can escape from the need for such caution, and where even the very survival of our species over Eternity may just be confronted with the possibility of extinction through carelessness or ignorance, or a shallow and selfish morality, or ideology or skepticism, or a universal involvement in petty and personal disputes between men fighting in diapers. (Phenomena we have seen often enough in World Wars and in Wars Ancient, but no less pathetic and mindless.)

In short, All of the Future hangs by a single tenuous thread from each and ever Present.

I wonder how long it takes till people will be on trial for their crimes against humanity.

Quoting Minnemike:913. AstroHurricane001:where do those graphs come from and how was the information put together? i've been interested in precisely those relationships, but that chart almost seems too simplified and nondescript for me to source (or take as fact). i'm skeptical of the sourcing and curious about it's merit. while that is how i expect things to trend out, i don't want to fool myself by believing what i want to see.

There is already sufficient evidence of an anthropogenic cause to justify action on global warming. Delay and denial has gone too far, and inaction is not an option. We have already wasted decades with debate supporting laisse-faire policies and we now simply cannot bet our lives on that remaining 5% that global warming is not anthropogenic and that it will not have any significant effects to our daily lives.

913. AstroHurricane001:where do those graphs come from and how was the information put together? i've been interested in precisely those relationships, but that chart almost seems too simplified and nondescript for me to source (or take as fact). i'm skeptical of the sourcing and curious about it's merit. while that is how i expect things to trend out, i don't want to fool myself by believing what i want to see.

It is not useful to try to bring up every possible piece of evidence to disprove the theory that AGW is occuring and that it is serious. By overfocusing on the details, one tends to miss the bigger picture. Doing this is not progressive, and is taking scientific skepticism too far, and is actually more ideological than scientific in motivation.

Abstract: This paper documents various unresolved issues in using surface temperature trends as a metric for assessing global and regional climate change. A series of examples ranging from errors caused by temperature measurements at a monitoring station to the undocumented biases in the regionally and globally averaged time series are provided. The issues are poorly understood or documented and relate to micrometeorological impacts due to warm bias in nighttime minimum temperatures, poor siting of the instrumentation, effect of winds as well as surface atmospheric water vapor content on temperature trends, the quantification of uncertainties in the homogenization of surface temperature data, and the influence of land use/land cover (LULC) change on surface temperature trends. Because of the issues presented in this paper related to the analysis of multidecadal surface temperature we recommend that greater, more complete documentation and quantification of these issues be required for all observation stations that are intended to be used in such assessments. This is necessary for confidence in the actual observations of surface temperature variability and long-term trends.

17 university profs as authors, including my friend Dr N-G at A&M, also associated with outing the Himalaya glacial claims...

Quoting casaturn:What would be left in the IPCC report if all the non-peer reviewed opinions were left out of it? And, if all your peers agree with your theory because it supports funding for you own pet project, why should anyone believe in the value of peer review anyway. Especially if the authors refuse to make the recommended changes anyway.

I'm having a really hard time trusting scientists these days. And I'm really disappointed in your conclusions Dr. Masters. They seem incredibly biased.

What would be left in the IPCC report if all the non-peer reviewed opinions were left out of it? And, if all your peers agree with your theory because it supports funding for you own pet project, why should anyone believe in the value of peer review anyway. Especially if the authors refuse to make the recommended changes anyway.

I'm having a really hard time trusting scientists these days. And I'm really disappointed in your conclusions Dr. Masters. They seem incredibly biased.

There is already sufficient evidence of an anthropogenic cause to justify action on global warming. Delay and denial has gone too far, and inaction is not an option. We have already wasted decades with debate supporting laisse-faire policies and we now simply cannot bet our lives on that remaining 5% that global warming is not anthropogenic and that it will not have any significant effects to our daily lives.

But the question becomes, if we can't prove global warming is caused by man, why change our way of life? I for one do what I can to protect the environment, but I won't go overboard unless man's cause of global warming is proven.

There is already sufficient evidence of an anthropogenic cause to justify action on global warming. Delay and denial has gone too far, and inaction is not an option. We have already wasted decades with debate supporting laisse-faire policies and we now simply cannot bet our lives on that remaining 5% that global warming is not anthropogenic and that it will not have any significant effects to our daily lives.

On August 20, 2009, there were 18 tornadoes in S. Ontario in one day, despite the relatively cool weather. Usually we only get about 15 in the entire province in one YEAR! Global warming does not increase total tornadic activity in North America, but it does move the tornado alley farther northeast.

The controversy and debate, by now, should have moved beyond whether climate change is happening and whether it is caused by man. By now, the debate should be about the solutions, and what to do to mitigate or adapt to climate change. Unfortunately, some people simply shoot down radical ideas as soon as they see one, and we're still stuck at step two. Delay in action due to debate is as serious as deliberate inaction due to political lobbying. If this has proven anything, it only proves that our traditional ideas about politics do not work and that conservative thinking can no longer survive on this planet. Denial is now funded by large corporations and governments, who care nothing for their people and everything about their mony, investing on a resource due to run out in a few decades. Too much politics have been injected into the scientific debate, which should have ended 20 years ago. Global warming doesn't care what your political party is. To solve this global problem, we need global cooperation. The faliure of the Copenhagen Conference solidly demonstrates that global cooperation is currently not possible due to all the political lobbying.

But the question becomes, if we can't prove global warming is caused by man, why change our way of life? I for one do what I can to protect the environment, but I won't go overboard unless man's cause of global warming is proven.